Across
1
Molten rock beneath Earth surface
2
Basic unit of life
3
Mass per unit volume
6
Our home planet
7
Reddish electrical conductor
9
Positive particle in nucleus
10
Natural satellite of Earth
12
Unit of energy
Down
2
Icy body with a tail near the sun
4
Naturally occurring inorganic solid
5
Nerve cell in the brain
8
Push or pull on an object
11
Form of thermal energy